Assignment for the Infrared Spectrum of Solid Sodium Propionate from Low-Temperature Measurements in Combination with ¹³C Isotopic Shifts

Abstract

The infrared spectra of CH3CH2COONa and its 13C-labeled modifications (1-13C, 2-13C, and 3-13C) suspended in KBr disks were measured in the region 4000 -200 cm-1 at room temperature and liquid nitrogen temperature. Overlapping complex band contours appeared in some regions of the room temperature spectrum, most notably in the region 1500 -1350 cm-1, where 5 fundamentals having contributions from the methyl deformation, methylene bending, and carboxylate stretching modes should occur. In contrast to this, excellent resolution was reached at the low temperature, from which all 22 fundamentals expected in the whole spectral region investigated were detected. A complete assignment of the fundamentals is proposed mainly on the basis of the characteristic isotopic shifts of the three 13C substituted sodium propionate species. A fair number of the fundamentals were found to feature coupled modes having contributions from several group vibrations.

Preparation and characterization of polypropylene/sodium propionate (PP/SP) composite films for bread packaging application

“…Further, SP exhibited several characteristic bands at 2972 and 2937 cm −1 arising from the CH 3 stretching vibration, 1563 cm −1 from asymmetric CO 2 stretching, and 645 cm −1 from CO 2 bending and asymmetric C―C―C stretching. The band observed at 507 cm −1 was assigned to in‐plane CO 2 rocking and symmetric C―C―C stretching . For the composite films, the intensities of the absorption bands at 1563, 645, and 507 cm −1 , which are related to CO 2 and C―C―C in SP, gradually increased with the SP content, as expected.…”

“…The band observed at 507 cm −1 was assigned to in-plane CO 2 rocking and symmetric C-C-C stretching. [32][33][34] For the composite films, the intensities of the absorption bands at 1563, 645, and 507 cm −1 , which are related to CO 2 and C-C-C in SP, gradually increased with the SP content, as expected. The increase in the intensity of the carboxylate group (COO − ) with a large dipole moment can be expected to cause an increase in the hydrophilicity of the PP/SP composite films.…”

Thermal decomposition of yttrium propionate: film and powder

“…) [33] it has been proposed that [27,30] a chelating coordination exists when Δν < < Δν Na-prop, bridging coordination occurs when Δν ≤Δν Na-prop , while monodentate coordination appears when Δν > > Δν Na-prop .…”

Estudo de espectroscopia raman da interação de dióxido de enxofre com dendrímeros de polipropilenoimina e polietilenoimina hiper-ramificadas

“…A banda em 1024 cm -1 pode ser atribuída a um CH2 rocking/twisting que normalmente é encontrado em sais de ácidos de ácidos carboxílicos como propionato de sódio [113]. Vemos que em PAA temos apenas uma região ligeiramente alargada de intensidade muita baixa nesta região.…”

“…A banda em 844 cm -1 pode ser atribuída tanto à s(C-N) de amida; como à (C-COOH). Vemos que no espectro de PAA esta banda é encontrada em  800 cm -1 (795 cm -1 ) que corresponde ao valor reportado para PAA [95]; nos sais de PAA esta banda é descrita como sendo mais deslocada ( 860 cm -1 , frequência Raman) e no espectro de sais de ácidos carboxílicos em  820 cm -1 porém atribuída à CH2 rocking [113].…”